Climate.gov has produced a video highlighting the importance and role of the Arctic Oscillation in understanding the cold temperature we experienced in the United States during March of this year and, conversely, the warm temperature last year.

Monday marks Earth Day — the environmental-awareness event inaugurated 43 years ago, just three years after the Super Bowl was born. Earth Day I in 1970 represented a massive change in the world’s consciousness about the environment, and arguably led to the founding of the Environmental Protection Agency and passage of the Clean Air and Clean Water Acts. The strange notion of “recycling,” which only a few oddballs had even heard of, suddenly entered America’s consciousness as well.

With all of that attention to the environment, though, nobody was talking back in 1970 about a bigger threat to the planet than air and water pollution: at the time, climate change wasn’t even a blip on most environmentalists’ radar. But annual average temperatures have been on an upward trend ever since — more in some places, less in others — thanks in large part to our emissions of heat-trapping greenhouse gases.

It’s true if you look at the United States as a whole (see below), and it’s also true if you focus in on any specific state. The graphic above shows the trend for : thanks to the natural variability of weather, some years have been warmer than average, others cooler. Overall, though, the trend is steadily up — by degrees per decade for since 1970 — and climate scientists are convinced that without action to limit greenhouse gases, that trend will continue.

You can find more detail about trends in annual temperatures for all the states, along with interactive graphics, in Climate Central’s report “The Heat Is On.”